WELL; Really? The Claim: Milk thistle combats liver disease.

By ANAHAD O'CONNOR

Published: July 31, 2012

THE FACTS

In the world of alternative medicine, milk thistle is the treatment of choice for liver disease, particularly chronic infection with hepatitis C.

Extracts of the plant, a member of the daisy family, have been used for ages to treat liver problems. About a third of people battling hepatitis C infection say they have tried milk thistle capsules, extracts or powders, a figure that helps explain the roughly $100 million in annual sales of the products.

Though studies in the lab have shown that milk thistle may protect and promote the growth of liver cells, clinical trials have been mixed at best, and many of the studies have not been well designed. So experts, while waiting for good data, have mostly cautioned that the jury is still out on milk thistle's effectiveness.

But now more evidence has come in: In a careful, double-blinded study financed by the National Institutes of Health, researchers at the University of North Carolina found that milk thistle had no real effect on people with chronic hepatitis C.

The study, one of the most rigorous to date on this topic, followed 154 people with the disease for 24 weeks. Some were given a placebo while others received silymarin, the active ingredient in milk thistle, three times a day in either normal or high doses.

By monitoring enzymes indicative of liver function, the researchers found that the herbal extract did not create any improvement compared with the placebo. Nor did milk thistle differ much from the placebo with regard to side effects.

THE BOTTOM LINE

Findings from one of the best studies of milk thistle to date suggest its reputation as an antidote to liver ailments may be overstated.

This is a more complete version of the story than the one that appeared in print.